1. Field of the Invention
The present invention relates to a solenoid valve assembly and more particularly to improvement of an electrically operated type valve which is operated in accordance with an energized and deenergized condition of the solenoid coil.
2. Description of the Prior Art
A conventional solenoid valve assembly is disclosed for example in U.S. Pat. No. 4,170,339 granted on Oct. 9, 1979 to Ueda et al. which sets forth an electromagnetic valve including a magnetic circuit formed by a stationary core and a movable core, or armature pivoted at one end of the stationary core and rotatable continuously between first and second positions with a free end positioned in opposed relation to the other end of the stationary core with an air gap therebetween. The armature is spring biased so as to remain in the first position and carries a valve head for engagement with a valve seat. The opposing ends of the stationary and movable cores are so shaped as to form in the air gap a first working section in which the main magnetic flux generates a vector component transverse to the length of the armature and a second working section in which the main magnetic flux generates a vector component parallel to the length of the armature. The resulting vector makes the angular displacement of the armature linearly proportional to the supply current. In particular, such conventional solenoid valve assembly includes an armature member of magnetic material pivoted on a recess on a knife edge, a valve member mounted on one end of the armature, a coiled spring connected at an opposite end of the armature to thereby bias the armature in a clockwise direction, and a magnetic circuit for urging the armature in a counterclockwise direction against the force of a spring to thereby operate the valve.
In the above valve arrangement, the durability of the valve may be lessened because both the recess of armature and knife edge portion are defaced by rubbing motion caused by rotation of the armature. Thus both the entire valve and armature are biased to the knife edge portion whereby the valve engages the valve seat at an angle of inclination in the clockwise direction against a horizontal direction of orientation of the valve seat.
Therefore, the valve does maintain sealing engagement with the valve seat.